I've been thinking about the candidates list(s) and I have a few semi random ideas.
Has everyone forget about the dicrepancy vs the cave list and the lighthouse list? While kate was crossed out in the cave, she was not crossed out in the lighthouse. Also, when Ilana was discussing the candidates she said there were 6 left. That included Jarrah, Ford, Kwon (I am assuming Kwon=1), Reyes, and Shepherd. That leaves one more. That would presumably be Locke. However, he was clearly dead at this point and Ilana was obviously aware of that. So that still leaves one more candidate: Austin. Somehow she was crossed off of MIB's (and Widmore's) list when she should not have been. I think this is important.
So how many are still left? Jarrah and Kwon are dead, so they're out. If you believe the once common theory that candidates can't kill others or they're out, then Ford is out. That leaves Sheperd and Reyes, and possibly Austen.
Given Kate's questionable status, I could see something very interesting happening. MIB figures out some way to kill off Hugo and (heavy favorite) Jack. Meanwhile Kate is still alive. MIB is super excited, thinks he's won, and tries to leave, but can't. Kate shows up and spoils the fun. Eventually he figures out that she was still a candidate, and realizes he is SOL.
There is one other thing I've thought about, which is kind of out there. What if being the candidate means nothing? Let me explain. I've realized there are three possible outcomes to the "game." The first, and most assumed, result is that MIB gets trapped on the Island. In that case, somebody needs to fill in for Jacob to hold MIB on the Island. (As I've been writing I've realized there is also case 1a where someone takes over for MIB. Still this case would have the MIB equivalent held on the Island by the Jacob equivalent.)
The second case is MIB dies (and no one takes over.) The third case might be the most shocking; MIB leaves the Island and everything is OK. In both these cases, there's not really any point in having some trap MIB if he's dead or gone.
There's a lot of possibbilites here, and porbably some things I haven't thought of. The candidates list has actually become pretty interesting now and even with only a few shows left there's still a lot of room for potential twist. It should be exciting to see it all play out.